Speed governing system



March 1942- D. s. BENNETCH 7 SPEED GQVERNING SYSTEM Fi led Au. 3, 1940 3 Sheets-Sheet 1 INVENTOR.

DAVID S BENNETCH BY am- ATTORNEY .March 31, 194-2. s BENNETH 2,278,100

SPEED GOVERNING SYSTEM Filed Aug. 3, 1940 3 Sheets-Sheet 2 mvzmon DA V10 5. BENNE TCH 5/ ATTORNEY March 31 1942. D. s. BENNETCH 2,273,100

SPEED GOVERNING SYSTEM Filed Aug. 3, 1940 3 Sheets-Sheet 3 mi M' ATTORNEY u w m M E F. 3 m 3 m \z A I g g S S .3. fi m S g n v k W. Q MQ A J 3 sm/Q3 5 Q Q 8 xxx x H llll I- 5 g .i. 53 .P\\ 2? s .3 Q Q? V I g 55 a S W M. Q Q i Q3 Q Patented Mar. 31, 1942 UNITED STATES PATENT OFFICE SPEED SYSTEM v David S. Bennetch, Sheridan, Pa.

Application August a, 1940, Serial 'No. 350,197 (01. 264-3) I 17 Claims.

The invention relates to speed governing devices and more particularly to speed governing devices for governing the speed of rotation of prime movers and the like.

The present invention involves the use of hydraulic mechanism for modifying the action of the conventional centrifugal governor, whereby greater sensitivity is obtained, i. e. large throttlemoving force and large throttle movement are obtained with small variations in speed; and whereby the throttle-moving force and throttle movement are independent of the particular speed at which the governor is set to govern. Th invention contemplates the use of a manually adjustable control for adjusting the set or governing speed to make the same governor capable of wide use, so that the same mechanism may be used for maintaining the same engine or difierent engines at widely different set speeds.

The invention in its specific form contemplates nected to the throttle or other speed controlling element of the engine to be governed. Fluid pressure is applied to the pressure chamber from a substantially constant source of pressure acting through a restricted passage. A second cylinder having a slidable plunger is connected to the pressure chamber, the cross section of the plunger being generally tapered or triangular and coopera ing with a grooved port on the first piston, whereby the pressure in said pressure chamber is available for exerting pressure on the plunger. The plunger is so arranged that with increase in fluid pressure, the area of the plunger exposed to the fluid pressure decreases, requiring a greater piston and throttle movement to build up sufflcient reactive force on the plunger to balance the increase in centrifugal force.

The manual adjustment for adjusting the governor to different set speeds may be made by changing the pressure exerted by a main spring against the centrifugal force exerted on said plunger and also shifting the center point of governing movement of the main piston. In this way less opposing force and less variation in that force is obtained with the corresponding lower centrifugal forces generated at lower speeds.

The invention also consists in certain new and original features of construction and combination of parts hereinafter set forth and claimed. Although the novel features which are believed to be characteristic of this invention will be par ticularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages, and the manner in which it may be carried out, may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof, in which Fig. 1 represents a main longitudinal section through the governor;

Figs. 2, 3 and 4 are detail sections on the lines 2-2, 3-3 and l- -lof Fig. 1;

Figs. 5 and 6 are details taken on the lines 55 and 6-6 of Fig. 1;

Fig. '7 is a perspective of the auxiliary plunger;

Fig. 8 is a diagrammatic assembly illustrating the manner of connecting up the governor to the throttle and to the oil pressure lines of a conventional gasoline engine;

,Fig. 9 is a diagram illustrating the function of the triangular or wedge-shaped auxiliary plunger;

Fig. 10 shows a longitudinal section through a modified form of governor; and

Figs. 11 and 12 are sections taken on the lines llll and l2|2 01' Fig. 10.

In the following description and in the claims, various details will be identified by specific names for convenience, but they are intended to be as generic in their application as the scope of the claims will permit.

Like reference characters denote like parts in the several figures of the drawings.

In the drawings accompanying and forming part of this speciflcation,certain specific disclosure of the invention is made for purposes of explanation, but it will be understood that the details may be modified in various respects without departure from the broad aspect of the invention.

Referring now to the drawings and more particularly to Fig. 8, the governing apparatus is shown applied to an ordinary gasoline'engine for purposes of illustration, although it will be obvious that the governing apparatus may be utilized to govern the speed of any type of engine, in cluding Diesels, steam engines, steam turbines. water turbines, etc. In Fig. 8, the'engine, which is denoted generally by I 0, has a carburetor ll feeding gas to intake manifold ll through a throttle casing IS. The throttle has a butterfly valve indicated by I2 and is pivoted within the casing 13 by a shaft 29.

The governor is denoted in general by i5. Its

drive is taken from the cam shaft, indicated by it, which drives the governor shaft l8 (Fig. 1) through a set of gears l'l.v It is obvious that, instead of the cam shaft, the drive may be taken direct off the ,crank shaft or distributor shaft or any other shaft having a definite driving relation with the engine speed.

The speeding up of the governor from rest (the position shown in Figs. 1 and 8) causes the spindle l9 to move to the left in Fig. 8. Spindle I9 is connected to a bell crank lever 23 pivoted on a bracket 22 secured to a part of the governor in the manner described more in detail hereinafter. A link 24 pivotally connects bell crank 23 to lever 25 pivoted to a part of the engine at 28, and link 21 pivotally connects lever 25 with arm 28 on shaft 29. It will thus be seen that movement of spindle l9 to the left in Fig. 8 imparts a closing movement to throttle l2. The operation of the governor apparatus utilizes oil which may be taken from the regular lubricating system of the engine, provided the engine is equipped with an adaptable lubricating system. In the event the engine is not equipped with such a hydraulic system, one will have to be supplied, possibly as an auxiliary, for the operation of the governor. In Fig, 8 the oil pump is denoted by 32. This may be an ordinary gear pump driven from the engine. The suction pipe is denoted by 35 and communicates with the bottom of crank case 31 which constitutes a sump for the lubricating oil. Pump 32 discharges through a pressure regulating valve, indicated by 33, which is usually a part of the lubricating system on the conventional gasoline engine, and thence to feed line 34 which connects with the governor l5. This oil, after being utilized by the governor, is led back to the crank case 31 through pipe 38. It will be understood that the pressure regulating valve 33 keeps the oil-pressure in pipe 34 at substantially constant value and that the regulating valve 33 discharges excess oil back into the crank case 31 when the pump 32 is rotated sufficiently fast to build up excess oil pressure.

Referring now to Figs. 1-7, the governor l comprises a pair of arcuate weights 38 pivotally connected by pivots 42 to extensions 48 on sleeve 39 secured to governor shaft ill by pin 41. The weights 38 have toes 43 which abut bearing collar 44 which in turn abuts valve sleeve 45. Valve sleeve 45 (Fig. '7) has a lower, generally triangular plunger 48 which prevents the valve sleeve 45 from rotating, although it may be moved axially as governor weights 38 fly out under the centrifugal force due to rotation of governor shaft l8. p

Thegovernor shaft I8 is journalled in tubular casing 58 which is threaded into the adjacent part, indicated by 5l, of the motor l0 and the weights 38 are enclosed in a weight chamber 49. The sleeve 39 and the collar 3i determine the axial position of governor shaft l8. Secured to the underside of weight chamber 49 by bolts slidable axially, but held from rotation by the fit of lever 88 in a slot 83 (Fig. 6). The adjustable sleeve 82 is closed by a plug 84 which tightly clamps the collar of bracket 22. The casing 52 is closed by a collar 81 having suitable packing 88 for keeping the hydraulic valve casing tight, yet permitting axial movement of sleeve 82.

Slidably mounted within the main cylinder 58 is piston 89 having a plunger 88 which has a piston fit with the cylinder 58. The piston 89 is elsewhere relieved, except for an annular flange having an annular groove forming an annular port ll closely fitting the walls of the cylinder 58. Passages I l and 10A connect the end of plunger 88 with the annular port H.

g The piston 89 is integral with spindle l9, to

53 is a hydraulic valve casing 52. A removable cover plate 54 issecured to casing 52 by bolts 55.

The valve casing comprises a main cylinder.

58 having an auxiliary cylinder 59 intersecting therewith which has the same cross section as its plunger 48. The casing 52 is provided with exhaust ports 80 which permit the oil to flow intothe weight chamber 49, whence it discharges through discharge pipe 38. Plug 8| closes the which is pinned a collar 12. A coil spring 13 acts between collar 12 and plug 84. This spring may be called the throttle spring since it exerts a force tending to impart an opening movement to the throttle. The position of these parts in Figs. 1 and 8 corresponds to full open position of the throttle.

The plunger 48 (as shown) has a generally triangular cross section (see Figs. 5 and 9), although it may have any cross section, depending upon the characteristics it is desired to impart to the governor. Its lower surface 14 is cylindrical, laid out on the same diameter as cylinder 58. Oil, being supplied through passage 58 into the pressure chamber 15, passes through passage 10 to annular port II, but, due to the close fit of annular port 'II with the walls of cylinder 58, no leakage can occur except where the walls of the cylinder 58 intersect cylinder 59. The oil thus escapes at the point between annular port H and the surface 14. This point is indicated by H and will be called for convenience the bleeding point. The amount of oil bled at this point will depend upon the relative position of pistons 48 and 89.

This 011 passes through the bleeding point 11 into the relieved portions on either side of annular port II and thence out through exhaust ports 88. It will be noted that the cross section of bleeding point 11 decreases as plunger 48 moves downwardly, assuming piston 89 remains fixed, and it also decreases when piston 89 moves to the left, assuming plunger 48 remains in fixed position.

The centrifugal force urging plunger 48 downwardly in Fig. 1 is opposed by the pressure of the oil acting through annular port II on the surface The force exerted by the oil pressure depends upon the value of the oil pressure in pressure chamber 15, which in turn depends upon the amount of oil escaping through the bleeding point 11, and the position of piston 89 which determines the area of plunger 48 exposed to the oil pressure from annular port "H.

The restricted passage 58 is sumciently small totake only a small part of the oil from the pressure side of the engine lubricating pump 32 so as' not to interfere with the regular supply of oil to'the engine bearings. The restricted passage 58 has the further function of permitting the pressure in the pressure chamber 15 to vary by variation in the size of the bleeding point 11. While pressure in the pressure chamber may vary considerably to obtain the necessary throttle movement, a comparatively small change r in the oil bled is necessary to obtain this pressure variation. The value of the pressure in the pressure chamber may thus be made substantially independent of variations in oil viscosity since any increase in oil viscosity tending to decrease the flow of oil through the bleeding point also restricts the flow of oil through the restricted passage 68.

In addition to the force of the oil pressure, the centrifugal force acting on plunger 48 is opposed by the main spring 8| which acts through the following linkage.

The U-shaped link 18 (Figs. 3 and '7) connects plunger 48 and a lever 18. The lever 18 is fulcrumed by projecting studs 80 fitting into bearings in casing 62 and cover 54. The spring II, which may be a simple leaf spring, has a rounded nose engaging the lever 19 and is rigidly secured to slide 82 fitting the bottom of casing 52. Slide 82 has a rod 83 projecting out through the casing which is closed by a gland and collar 84. The rod 83 may be connected to a handle (not shown) or may extend to any suitable point for manual movement of the slide 82 for manual adjustment of the speed at which the governor operates.

The movement of slide 82 also axially moves adjustable sleeve 62 by the action of lever 81 having cam surface engagement with the end of slide 82. Lever 81 is integral with lever 88 and is held in place by pivot 89, held between casing 52 and cover 54 (Fig. 6).

Movement of adjusting rod 83 to the right in Fig. 1 changes the governing speed for which the governor is set. Movement of thisrod 83 changes the point of engagement of main spring 8| and lever 19, which in turn changes the force applied to plunger 46 through link 18. Movement of adjusting rod 83 to the right also causes lever 81 to move downwardly, permitting oil pressure in pressure chamber 15 acting through throttle spring 18 to move adjustable sleeve 82 to the left in Fig. 1. ing sleeve 62 also shifts the path of movement of port 1 I It will be understood that to move the throttle I2 from full open to fullclosecl position, the annular port 1| must move through a good part of the length of plunger surface 14 and that the adjustment of sleeve 62 to the left in Fig. 1 for different set governor speeds shifts the path of movement of annular port 1| slightly to the left, depending upon how much decrease'in set speed is desired. The purpose of shifting the path of movement of port 1| will be described more in detail hereinafter.

In view of the right angled relationship between the axis of movement of spindle l9 and the length of long link 24, and in view of the mounting of the bracket 22 upon adjusting sleeve 62, the slight shift of the adjusting sleeve to, the left in Figs. 1 and 8 has no substantial effect on the position of throttle I2. Thus irrespective of the position of adjustable :sleeve 62, full range of movement of the annular port is maintained and corresponding full range of movement of (the throttle between open and closed position is maintained.

Inconsidering the operation of this governor care should be taken not .toconfuse the normal variation in speed at any particular nominal or set governor speed caused by load or other engine changes with the variation in governor speed caused by deliberate change in adjustment. The first variation is the natural variation in speed, present in all speed governors, in which the speed of the engine varies between limits, above and below the normal or set governor speed. This will be called, for convenience, the governing The movement of adjust-- variation. The second variation results from the voluntary adjustment for changing the set or nominal speed .at which the governor operates.

The governor functions as follows. The operation will be explained at the position illustrated in the drawings in which the governor is set for a maximum governing engine speed of say, 3000 R. P. M. An engine speed of 3000 R. P. M. does not necessarily mean that the governor shaft I. must rotate at 3000 R. P. M. In many cases it is desirable that the governor shaft rotate at a lesser speed. For example, the gears |1 may have such a speed ratio as to give a governor shaft speed of 500 R. P. M. with 3000 R. P. M. engine speed.

Assuming that the engine is at rest, the throttle l2 will be wide open, as shown in Fig. 8, and there will be no oil pressure in the cylinder. 68. As soon as the engine starts, the oil pressure is built up in the pressure end 16 of main cylinder 68, which forces the main piston 66 to the left in Fig. l, gradually closing the throttle. The engine speeds up, the weights 88 moving the auxiliary piston or plunger 46 downwardly, which decreases the area of discharge between the piston port 1| and the triangular face 14 of the plunger (bleeding point 11), which in turn builds up more oil pressure in the cylinder, causing the throttle to close still more. Downward movement of the auxiliary plunger 46 also gradually increases the pressure in the main spring 8|.

The engine continues to build up speed until the auxiliary plunger 58 is moved down sufllciently to build up sufficient oil pressure to close the throttle sufficiently to decrease the fuel to that necessary to maintain the engine at its set speed at the particular load it is driving. If the .load'should increase, the governor speed drops toward its lower limit and the oil pressure and main spring 8| will move the auxiliary plunger 46 upwardly, increasing the discharge at the critical bleeding point 11, reducing the oilpressure in the cylinder 58 and permitting the throttle to open to increase the fuel sufficiently for the increased load. I

- If the load should decrease, the governor speeds up, moving theplunger 46 downwardly, decreasing thedischarge at the bleeding point 11, increasing the oil pressure in the main cylinder 58, causing the throttle to move towards closed position which decreases the fuel to correspond to the decrease in load.

It will be noted that the maximum range of movement of annular port 1| at any set speed is a good part of the length of cylindrical surface 14. The movement is capable of moving the throttle from between full open and full closed positions. The length of this range of movement 18 substantially thesame at all set speeds, the position varying slightly due to adjustment of the sleeve 62, as described above;

In the ordinary cycle of operation at any set plunger 46 and also on position of main piston 68, and plunger 48 will execute acyclic movement necessary to cause necessary adjustment of bleeding point 11. In any case the maximum movement of plunger 46 is small and the corresponding movement of the centrifugal weights 38 is also small.

The generally triangular or trapezoidal shape of the auxiliary plunger 48 with the narrow end of the triangle at the high pressure end of the range of movement of main piston makes the governor more sensitive, i. e. greater throttle movement is provided with a given cyclic variation in speed. As stated above, the cross section of the plunger may also have convex or concave sides to give the governor the desired characteristics.

It will be seen that, as the main piston 88 moves to the left in Fig. 1, increase in oil pressure is applied to the end of the auxiliary plunger 46,

but at the same time the effective area of surface H exposed to oil pressure decreases. The total hydraulic force is a product of the oil pressure times the effective area of the auxiliary plunger exposed and this total hydraulic force preferably should increase with increase in speed to obtain stable governing action. However, because of the decrease in area exposed of the auxiliary plunger with the closing of the throttle, a larger increase in oil pressure is required to generate the necessary hydraulic force to overcome the increase in centrifugal force caused by increase in speed, hence providing a greater throttle movement and greater sensitivity than would be obtained if there were no decrease in area exposed of the auxiliary plunger to the piston port 1|. The decrease in area may compensate for a too rapid build-up of the force exerted by the main spring 8|. It is obvious from the above that a comparatively small change in centrifugal force is sumcient to move the throttle between full open and idling positions.

From the above it will be seen that the cen trifugal force exerted on the auxiliary plunger I6 is opposed by two forces, (1) the hydraulic force exerted by the oil pressure over the variforce and the arithmetical variation in centrifugal force varies at the diflerent set or governing speeds with any given permissible governing variation in speed, it is desirable that the opposing forces and the governing variation in these forces vary in a similar manner.

Consider, first, the opposing force of the main spring 8|. In the position shown in Fig. 1, the main spring is exerting a force on the auxiliary plunger corresponding to its uppermost position, a position which it will never take when the governor is functioning since any substantial speed imparted to the governor will cause the free end of lever 19 to clear the outer wall-of cylinder 58. The force exerted by the main spring 8| will be less than that necessary to balance the centrifugal force by the amount of hydraulic force. The main spring may be a simple spring. obeying Hooke's law, the stress exerted by the spring being proportional to the strain, 1. e. its distance from its position of no stress. As the auxiliary plunger 46 moves upwardly or downwardly from its mean governing position corresponding to the set governor speed, the force exerted by main spring 8! decreases or increases.

when the governor is adjusted for a lesser set or governing speed, the construction is such that the mean force exerted by the main spring 8| on the plunger 46 is less and the governing variation in this force is also less. To obtain this adjustment, the adjusting rod 83 is pulled out to place the end of the main spring II in such a position on the lever 19 that the average pressure exerted on the auxiliary plunger ll is less than the average centrifugal force at that speed to. allow for the hydraulic force.

Downward and upward movement of the auxiliary plunger 46 will cause a corresponding increase and decrease in the force exertedby the main spring, but this variation will be less for the lower set speed because the further adjusting rod 83 is pulled out, the less the movement of spring 8| with the constant governing movement of plunger 46 because of the change in leverage of lever I9.

The manner of obtaining different mean or average hydraulic force and difference governing variations therein for the different set speeds will be understood from the following explanation:

When the adjusting sleeve 62 is moved to the left in Fig; 1, it will be understood that the amplitude of movement by piston 69 does not. change. but merely the end positions of the range of movement of the annular port II. Thus, full movement of the throttle I2 between full open and full closed positions is obtained for all set governing speeds.

The oil pressures at the extreme ends of the governing movement of the main piston 69 is constant, irrespective of the set governor speeds since the force required to overcome the throttle spring 13 remains the same. However, th adjustment of the adjusting sleeve 62 to the left in Fig. 1 for lower set speeds exposes smaller areas of surface 14 to annular port H, which means less average hydraulic force, the lower the set speed.

The adjustment of adjusting sleeve 62 to the left in Fig. 1 also changes the arithmetic variation in hydraulic force applied to the plunger 46 due to the governing variation. Since the exposed areas at the left-hand end of the plunger 46 in Fig. 1 are smaller, the percentage change in exposed area of surface 14 exposed to port H is greater at the left-hand end of the path of movement of the annular port 1| than at the right-hand end. This greater reduction percentage-wise in the exposed area at the left-hand endof the movement of port 1| with adjustment of sleeve 62 means greater reduction percentagewise in the upper limit of the governing variation in hydraulic force and accounts for the arithmetical decrease in governing variation of the hydraulic force at lower set govemer speeds.

The arithmetic decrease of the governing variation in hydraulic force with adjustment of sleeve 62 from higher set governor speeds to lower set governor speeds will be understood by reference to Fig. 9 which represents the projection of plunger 46 upon a plane intersecting the axis of main cylinder 58 at right angles to the line of movement of plunger 46. The dotted lines indicate the extension of the convergent sides to complete the triangle. The vertical lines in Fig. 9 may represent the center lines of the various areas exposed to oil pressure when the annular piston port H travels along the auxiliary plunger l6.

These areas are proportional to the lengths of the vertical lines, which in turn are proportional to their distance from the apex of the triangle.

The horizontal lines represent the full throttle movements at the different set speeds, line representing the highest set speed which the governor is capable of functioning, line 93 the lowest set speed and lines 9| and 92 representing intermediate set speeds.

Giving the vertical lines in Fig. 9 arbitrary values to indicate units of area, line 90 may indicate the path of operation between areas of 12 and 24 units and line 93 may indicate the path of operation between areas of 9 and 21 units.

- Assuming that the hydraulic pressure in each case varies from 12 units at the high pressure end to three units at the low pressure end, we have, as the hydraulic forces at the ends of the path indicated by 90, forces of 144 and '72 units; at the ends of the path indicated by 83, forces of 108 and 63 units. This gives a differential in hydraulic force between the ends of the path 90 of 72 units and between the ends of the path 93 a differential of 45 units. Thus, it will be seen that not only are the hydraulic forces less as the adjusting sleeve 62 is moved to the left in Fig. 1, but also the differences between the forces at the extreme ends of piston travel are less.

The amount of force exerted by the main spring 8| and that exerted by hydraulic pressure on plunger 46 will depend upon design. The exact pattern of variation in hydraulic pressure applied to plunger 46 as port II moves to the left in Fig. 1 will also depend upon design. The side walls (extending from right to left in Fig. 9) of the plunger 46 may be straight as indicated; they may be convex or concave, or of irregular shape or parallel, to' obtain the desired hydraulic pattern.

In some cases, the main spring 8| may be omitted entirely, in which case the end face I4 of the hydraulic plunger 46 will be so shaped to supply all of the force necessary to oppose the centrifugal force generated by the rotating weights 38. In this case the adjustment of sleeve 62 will provide all the necessary adjustments to adjust the governor to different set speeds. It is obvious that the feature of adjusting sleeve 62 may also be omitted entirely, making the governor a single speed hydraulic governor.

In case the spring 8| is also used, as above stated, the relative forces supplied by this spring and by hydraulic pressure may vary with design. The following description is given as an example of one combination of hydraulic and spring forces.

Assume that at any given set speed the engine is running with practically maximum load and with the throttle almost wide open. The governor will then run near its lowest limit of speed for that particular set speed, generating corresponding centrifugal force. The spring pressure 8| and hydraulic pressure will also be near their minimums for that set speed.

Assume now that all or a part of the load is removed. This causes the engine to speed up a small amount but sufflcient to obtain governing action. As governor shaft I8 speeds up, the governor weights 38 fly out. The build-up in centrifugal force applied to plunger 46 is due to two causes: (1) the build-up because of increase in governor speed and (2) the build-up because of increase in radius of weights 38.

Since the outwardmovement of weights 38 causes a downward movement in plunger 46 and in spring 8|, the design may be such that the build-up in spring 8| balances the build-up in centrifugal force due to increase in the radius ofthe weights 38. This is possible since the centrifugal force increases directly with the distance of the weights from the center of rotation and the spring 8|, being a simple spring, the force built up is directly proportional to the distance from its position of no force or rest.

The build-up in centrifugal force due to increase in speed varies as the square of the speed and this may be taken care of by the build-up in hydraulic force. As stated above, the surface I4 may be so shaped as to provide a build-up in hydraulic force to correspond with the square law of the governor or to follow any other desired law to provide good governor operation.-

Thus a governor is disclosed which is sensitive in that it will maintain speed close to the set speed irrespective of variations in load; it is quick in that it will respond quickly to variations in speed and yet will not hunt; it exerts large force through a large distance for operating the throttle or other mechanismfor controlling the speed of the engine or other prime mover. Furthermore, the governor is adjustable in that the same governor may be used to maintain an engine at different speeds. This is especially desirable on engines desired for general use, such as tractors on farms where a uniform speed is desired for one job and another uniform speed for another job.

A further advantage of the governor is that the correcting force applied by the governor is independent of the set speed. Furthermore, the governor will remain accurate with wide temperature variations, the change in viscosity of the oil having-little or no effect on the governor. The governor is comparatively inexpensive to build and requires but a comparatively small centrifugal unit to supply the speed responsive control. Further, by giving the proper pattern to the cross section of the plunger, with or without the main spring, any desired characteristics can be obtained.

Referring now to Figs. 10-12, a modified construction will be described. The operation of this governor is based upon that described above, but a somewhat different construction is provided for moving the adjusting sleeve and for varying the amount of spring force.

In this form the auxiliary plunger is denoted by I 00; the main piston by IOI; the main cylinder by I02; the annular port by I03; bleeding point by I04; the spindle by I05; the throttle spring by I06; the adjustable sleeve by I08; the oil supply pipe by I09 and the restricted passage by H0. The plunger I00 has an end face III and the cooperation between end face III and annular port I03 is the same as that of Figs. 1-9. The same fly-weight construction is used for operating the plunger I00.

The adjusting sleeve I08 is given an axial movement by rotating the sleeve by lever I I2 secured to the sleeve. The sleeve has a helical groove I I 3 in which works a set screw I screwed through the wall of the hydraulic casing H5.

The main spring 6 is of spiral construction as indicated particularly in Fig. 12, one end being secured to a reduced part of sleeve I08 by a set screw III. The free end of leaf spring II6 abuts an offset I2I on lever II8 having a pivot H9 pivoted to the plunger I00 and a pivot I20 slidably erligaging a recess I22 in the hydraulic casing 5. i Thus the main spring II6 exerts an upward force upon plunger I00 at a substantially fixed leverage, but its effective length, and-hence the force exerted by the spring I I6, may be varied by rotating the adjusting sleeve' I08 by arm II2. Thus as arm III is rotated by hand adjustment to move sleeve I08 to the left in Fig. 10 to prosame.

vide lower hydraulic force, the main spring H6 is rotated to engage lever IIO nearer the free end of the spring II6 to give less spring force.

The spindle I05 is connected to the throttle I30 indicated diagrammatically in such manner that sleeve I08 may be rotated to adjust the set speed without affecting the throttle position.

The throttle I30 is connected to suitable linkage indicated by I3I, which in turn is connected to a bell crank lever I32 pivoted to a fixed point I33 on theengine frame. Lever I32 has a forked end I34 engaging the opposite flat faces I35 of a block I36 having trunnions I" engaging in slots in the forked end I34. Block I30 is free to move on spindle I05 under control of a pin I31 fixed to the spindle I05 working in a helical slot I30 in block I30. Spindle I05 has a straight groove I39 in which works a set screw I40 secured to sleeve I08.

The pitches of helical slots H3 and I30 .are the When adjusting arm H2 is rotated to .move sleeve I to the left in Fig. 10, spindle I is also rotated as it is carried axially along with sleeve I00. Block I35 is prevented from rotating by bell crank I32 and thus rotation of spindle I05 merely rotates pin I3'I in groove I30 without moving bell crank lever I32. Movement of main piston IOI under hydraulic pressure, however, to the left in Fig. will act to close the throttle I30 in a manner similar to that described -in connection with Figs, 1-9.

The operation and adjustment of the form shown in Figs. 10l2 are practically the same as that described above in connection with Figs. 1-9 and therefore it is not necessary to make any further comment on the operation and adjustment of this modification.

While certain novel features of the invention have been disclosed and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the-invention.

What is claimed is:

Y 1. In a governor, a cylinder having a plunger therein, said plunger having a generally triangular cross section and a cylindrical end face, a second cylinder intersecting said first cylinder and having a piston therein and an annular port engaging the cylinder wall of said second cylin plunger, the shape of said plunger being such as to cause the amount of end surface exposed to said port to decrease as increase in pressure in saidpressure chamber moves said port along said end surface, whereby to increase the movement of said main piston necessary to build up sufiicient pressure in said pressure chamber to overcome the force applied to said plunger.

4. In a governing system, a main cylinder having a pressure chamber, a piston in said cylinder for exercising speed controlling action, an auxiliary cylinder intersecting said main cylinder, a plunger in said auxiliary cylinder having a converging cross section and a cylindrical end surface, said piston having an auxiliary port cooperating with the end surface of said plunger, the shape of said plunger being such as to cause the amount of said end surface exposed to said port to decrease as increase in pressure moves said port along said surface, means supplying said pressure chamber with liquid, and a spring opposing the liquid pressure applied to said piston.

5. In a governor, a governor shaft, governor weights pivoted to said shaft, a sleeve axially slidable on said shaft, said governor weights having parts to exert pressure on said sleeve, a lever having one end pivoted to a fixed point, a link connecting the other end of said lever and said sleeve, an adjustable slide,-a leaf spring secured to said slide having its free end engaging said lever, means for adjusting said slide, whereby said spring engages said lever at different points whereby to apply lesser mean forces to said sleeve and lesser arithmetical variations in said forces for lesser governing speeds, and means responsive to movement of said sleeve for exercising speed controlling action.

6. In a centrifugal governor, a governor weight, a governor shaft, a slidable plunger adapted to move axially by movement of said weight, said plunger having a variable cross section and a control surface, a member having a port having close relation to said control surface and movable lengthwise thereof, means for supplying fluid under pressure to said port, a holder having "means for determining the path of said port,

der and closely associated with said "cylindrical end face, means for supplying said second cylinder with liquid, the leakage between said an- 2. In a device of the character described, a. cylinder having a plunger therein, said plunger having a generally variable cross section and an end face, a second cylinder intersecting said first cylinder and having a piston therein and a port closely associated with said end face, means for supplying said second cylinder with fluid, the leakage between said port and said end face determining the pressure in said second cylinder for operating said piston.

'3. In a governing system, a device responsive sure chamber, means supplying fluid to said chamber, a piston in said cylinder, an auxiliary cylinder intersecting said main cylinder, a

means whereby the relationship between said surface and said port exercises speed controlling action, and means for adjusting said holder to adjust said path with respect to said surface to obtain different pressure characteristics, whereby less force is applied to said plunger and less governing variation in said force with lesser set speeds.

7. In a centrifugal governor, governor weights,

a governor shaft, a sleeve on said shaft to which said weights are pivoted, a slidable plunger adapted to move axially by movement of said weights, said plunger having a triangular cross section and a cylindrical lower surface, a member provided with a port'having close relation v to said cylindrical surface and movable lengthplunger operated by said speed change device,

and located in said auxiliary cylinder and having a converging cross section, said piston having a wise thereof, means forv supplying fluid under pressure to said port, a throttle connected to -move with said port, a holder having means for determining the path of said port, means whereto speed change, a main cylinder having a pres-- obtain different pressure characteristics, whereby less'mean force is applied to said plunger and less governing variation in said force with lesser set speeds.

8. In a speed governing device, a casing comprising a main cylinder having a pressure chamber and an auxiliary cylinder communicating with said main cylinder, main and auxiliary pistons in said cylinders respectively, a source of substantially constant fluid pressure, a restricted passage connecting said source and said pressure chamber, a speed responsive device connected to said auxiliary piston, a speed control device connected to said main piston, a port movable with said main piston and having a passage connecting with said pressure chamber, said auxiliary piston having a generally triangular cross section, a throttle spring opposing the fluid pressure exerted on said main piston, whereby increase in speed moves said auxiliary piston towards said port, causing an increase in oil pressure in said pressure chamber and movement of said main piston against said spring, the area of said auxiliary piston exposed to said oil pressure in said port decreasing with movement of said main piston. g

9. In a speed governing device, a pressure chamber having a main cylinder, an auxiliary.

cylinder communicating with said main cylinder, main and auxiliary pistons in said cylinders respectively, a source of substantially constant fluid pressure, a restricted passage connecting said source and said pressure chamber, a speed responsive device connected to said auxiliary piston, means cooperating between said pistons whereby movement of said auxiliary piston causes movement of said main piston and the movement of said main piston changes the area of said auxiliary piston exposed to the pressure in said chamber, a holder having a spindle slidably mounted therein connected to said main piston, a biasing spring for biasing said main piston against the pressure generated in said chamber, means for adjusting said holder to change the midpoint of movement of said main piston with respect to said auxiliary piston, a main spring opposing the speed responsive force applied to I said auxiliary piston, means for adjusting the pressure exerted by said main spring on said auxiliary piston and for adjusting said holder to change the force exerted by the fluid pressure on said auxiliary piston to correspond to the change in speed responsive force at the different set governor speeds.

10. In a speed governing system, a casing comprising a main cylinder having a port in the side wall thereof and a pressure chamber, an auxiliary cylinder connected to said port, a plunger slidable in said auxiliary cylinder, said plunger having a generally triangular cross section and a curved lower surface, a main piston slidable in said main cylinder and having an annular groove communicating with said pressure chamber and cooperating with said curved lower surface to form a critical bleeding point, said main piston having a spindle adapted to connect with a throttle or the like, an adjustable sleeve surrounding said spindle and slidable in said casing, an abutment secured to said spindle engageable with oneend of said sleeve, a spring between said abutment and the other end of said sleeve, a fulcrum secured to said sleeve, a bell crank pivoted to said fulcrum and having one arm pivoted to said spindle, a speed control member for controlling the speed of the device to be governed, a link extending from the other arm of said bell crank to the speed control member at substantially right lever arm pivoted in said casing, a link connecting said plunger and the free end of said lever arm, a slide in said casing, a main spring secured to said slide having its free end engaging said lever arm, a second bell crank lever pivoted in said casing and having one arm engaging said adjustable sleeve and the other arm engaging said slide, whereby movement of said slide changes the average force exerted by said main spring on said plunger and the central position of said annular groove with respect to said plunger, a centrifugal governor adapted to be connected to the device whose speed is to be governed for moving said plunger, a source of substantially constant fluid pressure, and a restricted passage connecting said source to the pressure end of said main cylinder.

11. In a speed governing system, a casing comprising a main cylinder having a port in the side wall thereof and a pressure chamber, an auxiliary cylinder connected to said port, a plunger slidable in said auxiliary cylinder and having a curved lower surface, a main piston slidable in said main cylinder and having an annular groove communicating with said pressure chamber and cooperating with' said curved lower surface to form a critical bleeding point, said main piston having a spindle adapted to connect with a throttle or the like, an adjustable sleeve surrounding said spindle and slidable in said casing, an abutment secured to said spindle engageable with one end of said sleeve, a spring between said abutment and the other end of said sleeve, a helical groove and projection connection between said sleeve and casing, a feather keyway connection between said sleeve and spindle, a block having a helical groove and projection connection with said spindle, a control member for controlling the speed of the device to be governed, connections between said block and said control member, a

variable force lever arm having one end pivoted" to said plunger'and the other end pivoted to said casing, a spiral main spring secured to said ad- .justable sleeve and having its free end engaging said lever arm, an arm for adjustably rotating said adjusting sleeve, whereby movement of said sleeve changes the average force exerted by said main spring on said plunger and the central position of said annular groove with respect to said plunger without afiecting said throttle, a centrifugal governor adapted to be connected to the device whose speed is to be governed for moving said plunger, a source of substantially constant fluid pressure, and a restricted passage connecting said source to the pressure end of said main cylinder.

angles to the axis of said spindle, a variable force 12. In a governing system, a main cylinder, an auxiliary cylinder intersecting said main cylinder at the side thereof, a piston in said main cylinder, 9. plunger in said auxiliary cylinder, said piston having a part closely associated with the end face of said plunger, means for supplying said second cylinder with fluid, the leakage between said part and said end face determining the pressure in said main cylinder for operating said piston, the movement of said piston determining the area of said end face exposed to the pressure in said main cylinder, a centrifugal governor exerting pressurev on said plunger against said fluid pressure, and a spring exerting pressure on said plunger against the governor pressure.

13. In a governing system, a speed responsive centrifugal governor having a governor weight, a fluid pressure chamber, an element in said applying a spring force to said element, said fluid and spring forces being so arranged that variation in fluid force corresponds to variation in governor force due to speed variation and variation in spring force corresponds to variation in governor force due to change in radius of said govemor weight, and means for operating the device to be governed by change in fluid pressure in said chamber.

14. In a governing system, a main cylinder having a pressure chamber, an auxiliary cylinder intersecting said main cylinder, a plunger slidable in said auxiliary cylinder, a main piston slidable in said main cylinder and having a part cooperating with the end surface of said plunger to form a critical bleeding point for said chamber, a spring opposing movement of said main piston, a source of fluid pressure, a passage connecting said source and said pressure chamber, the area of said end surface exposed to pressure in said chamber changing with movement of said main piston, a speed responsive centrifugal govemor having a rotating governor weight connected to move said plunger, means responsive to pressure in said pressure chamber for connection to the control element of the device to be governed, and a simple spring opposing the movement of said plunger toward said main piston, the change in force due to fluid pressure on said plunger corresponding to change in force exerted by said centrifugal governor due to change in speed, the change in force on said plunger due to movement of said spring corresponding to the change in force exerted by said centrifugal governor due to change in the radius of said governor weight.

15. In a governor, a holder having a movable element therein, said element having a face extending transverse to the direction of movement of said element, asecond element in said holder movable along a line transverse to the movement of said first element and comprising wall members forming a port therebetween disposed in close relation to said face and movable thereacross, means for supplying fluid pressure tosaid port, and means for exposing varying areas of said face to said port as the latter moves across said face.

16. In a device of the character described, a cylinder having a plunger therein, said plunger having a generally variable cross section and an end face, a second cylinder intersecting said first cylinder at an angle, a piston in said second cylinder having rib-like members extending across and closely associated with said end face and defining a port, means for supplying said second cylinder with fluid, the leakage between said port and said end face determining the pressure in said second cylinder for operating said piston.

17. In a governing system, a main cylinder having a pressure chamber, an auxiliary cylinder intersecting said main cylinder, a plunger slidable in said auxiliary cylinder, a main piston slidable in said main cylinder and having a part cooperating with the end surface of said plunger to form a critical bleeding point for said chamber, biasing means opposing movement-of said main piston. a source of fluid pressure, a passage DAVID s. BENNETCH. 

